Bamboo is a lignocellulosic material widely used throughout Asia as a building material because of its high strength, durability and excellent dimensional stability, as well as its ready supply and rapid replenishment—bamboo grows very rapidly, reaching full maturity within 2 to 6 years, while even the fastest growing wood tree species take as long as 15 to 30 years to grow to full maturity.
However, in addition to these advantages, bamboo also has a number of disadvantages. Since bamboo is hollow it cannot be processed into solid lumber board or planks.
And not only is it impossible to make solid lumber from, but bamboo can also not be processed by the conventional techniques used to make wood composite materials. For example, it is difficult to make plywood from bamboo because the bamboo culms are too thin to cut plywood veneers from. Nor has bamboo been successfully processed by techniques used to make strand composite wood materials (which are composite materials made from resin-coated strands given a preferred orientation and deposited in that orientation on an underpassing conveyor belt).
Despite these disadvantages, because of bamboo's ready supply and excellent performance characteristics, manufacturers have developed techniques to make wood composite materials out of bamboo. For example, composite bamboo structural panels may be made by hand-cutting bamboo strands from the outer part or surface of a bamboo culm, and then weaving (again typically by hand) the strands into mats. These hand-cut, hand-woven bamboo mats are then stacked together along with several other similar mats and the mats then pressed together under high temperature.
The problem with this method of manufacture of the bamboo boards is that it is time consuming; the steps of cutting the bamboo strips and then weaving the bamboo strips into the form of a mat take a significant amount of time. And not only are these processes time consuming, but they can lead to significant defects in the final board product. For example, internal gaps created by the layering of several of the mats on top of another can result in the production of holes or other defects in the board that can lead to failure. Additionally, bonding two woven bamboo mats together involves bonding together two mating surfaces, which is an additional source for defects. Yet another disadvantage of the aforementioned processes is that because they are composed of large numbers of bamboo layers, they are require very high doses of resin per layer, which adds greatly to the price of the product during periods of high petroleum prices.
Given the foregoing there is a need in the art for structural bamboo panels that are either partly or completely composed of bamboo, have fewer defects, do not require a lengthy manufacturing process, and consume a smaller amount of petroleum-based products.